Manufacture of hollow sheet metal shapes



July 28, 1931. o. REEFURTH MANUFACTURE OF HOLLOW SHEET METAL SHAPES Filed May 9, 1929 2 Sheets-Sheet l In venfo r: 0H0 Red furl/1 5y;

July 28, 1931. o. REIFURTH 1,816,293

MANUFACTURE OF :HOLLOW SHEET METAL SHAPES Filed May 9, 1929 2 Shets-Sheet 2 FILZ. I

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Patented July 28, 1931 OTTO BEIIUBTH, OF IMMIGBATH, GERMANY OF HOLLOW SHEET METAL SHAPES Application filed May- 9, 1929, Serial No 861,686, and in Germany November 20, 1928.

My invention relates toa method of and apparatus for making hollow sheet' metal shapes, for instance fittings for the connection of pipes. It is an object of m invention to provide shapes of the kind escribed which are more suitable for high pressures and more satisfactory in a general waythan the cast iron fittings which were employed heretofore.

To this end I make such shapes or-fittings from punched sheet metal blanks which are forged into the shape of one half of the finished part, and I connect two halves by mechanical or electrical welding. Prefer- |5 ably the welding seams are arranged so as to coincide with the axial planes ,of the parts which are to be connected by the fittings. For instance in a fitting for connecting pipes as will be described further below, the seams extend in the axial planes of the pipes to be connected.

'As mentioned above, cast fittings are not capable of withstanding high pressures and cannot therefore be used in pi e lines'in which such pressures prevail. asting fittings are also subject to considerable wear and, if threaded, have a tendency to breakat the throat of the threaded -portions.

It has also been suggested to bore and ta rolled solid blanks, but this mode of procee ing is extremely wasteful. It has also been proposed to veloped'size of the fittings from sheet metal, to forge them, to sha and to: connect them by. manual welding, bit this method is uneconomic and it has beenattem ted to improve it by cutting tubular blan s to shape and connecting t ese' shapes by welding. This, however, involves the drawback that the blanks must be cut to penetration curves and'must be welded along such curves, resulting in welding seams which are in an unfavorable position with respect to the forces acting on the fitting. 46 These drawbacks are overcome according punch flat blanks to the de-' to my invention in which two flat identical. blanks the configuration of each of which constitutes if developed about one half of the finished article are forged into the desired shape by means of dies and are then welded in an electric welding machine of some suitable type. lVelding additions are made when punching. By so arranging the welding seams that they coincide with the axial planes of the parts'which are to be connected y the fittings, their strength is greatly increased. In the drawings aflixed to this specification and forming part thereof a punching and welding machlne and its blanking and forging dies embodying my invention and vanous stages of manufactures of a T for connecting three pipes are illustrated .d iagrammatically by way of example.

In the drawings Fig. 1 is an elevation of the punching and fogging machine, partly in section,

ig. 2 is an elevation of the welding 'ma chine to which the forged blanks are delivered from the punching machine,

7!) Fig. 3 is a section of the blanking die of the punching machine, 1 Fig. 4 is a plan view of the female forging die, viewed from below,

I Fig. 5is a. section on the line 55 in Fig. 4, dJFig. 6 is a plan view of the male forging Fig. 7 is an elevation of the two halves of a fittmgready for welding,

Fig. 8 is an end elevation of the blank, viewed from the left in Fig. 7

Figs. 9 and 10 are elevations of the finished fitting, viewed in the same direction as Fi 7 and 8.

ferring now to the drawings and first '85 .toFigs. 1 and 2, 9 is the frame of the punching machine, 10 is a unch which is/arranged to reciprocate in the rame of the machine and is operated by suitable means (not shown). 11 is a blanking die secured-in the frame 9 is rocking lever pivoted in t".

below the punch 10, the punch and the hole in the blanking die 11 being shaped to the development of the halves from which the fittings are Welded plus a Welding addition, l2 is a sheet metal strip which is fed below the punch 10 by means of rollers 13, 13, is a slide supported for reciprccatory movement in a guide 7 of the frame 9, 15 is e' ferns" J die inserted in a cavity of the slide 8 and frame 9 I and arranged to reciprocate the slide 8, rvh rocking movement is imparted to the 1?.- cy suitable means (not shown).

In operation a 12a is punched the strip 12 efitr the slide 8 has been re-- trusted into the position illustrated in l 1" 1, end is left in hlanhing f 8 with the :Ecmsle die is now u vunced so as to bring the die into registcwith the blanking die 11 and s male die the end of a heed 5 isthen advanced intothe die through. the blanking die ll. The blank is forged into the T illustrated in llig. 8, Which comprises a semi-cylinder l plus Welding additions extending at right angles to the direction in which the slide 8 reciprocates, and a semi-cylinder 1%, also plus WElCling additions, extending in parallel to the direction of reciprocation.

The forged blank is noW delivered to a chute 17 and taken to the Welding machine 18, in the jaws 2 and 3 of which two forged blanks are placed in such position that their edges will meet when the jaws are closed. Current is applied and the blanks are Welded into the finished fitting illustrated in Figs. 9 and 10, Which is ready for threading.

In the foregoing I have described the manufacture of fittings for pipes, but I Wish it to be understood that many other articles may be manufactured according to my invention, such as bends, cross-shaped articles, etc.

I Wish it to be understood that I do not desire to be limited to the exact details of construction shown and described for obvious modifications will occur to a person skilled in the art.

In the claim afiixed to this specification no selection of any particular modification of the invention is intended to the exclusion of other modifications thereof and the right to subsequently make claim to any modification not covered by the claim is expressly reserved.

A shaping machine for making hollow metal shapes two of which are subsequently to be Welded into a finished article, comprislug a. fixed blanking die and a reciprocating punch for cutting from sheet metal a; blank corresponding to the spread-out shape of the finished half of said article, means on said blanking die for retaining the blank therein, a male die arranged below said blanking die in line With said punch and adapted to misses 

